Title text:
Imagine you could ride alongside a sound wave. It would probably be pretty cool, right? We're putting in a departmental budget request to buy a really fast plane so we can check it out.
Transcript:
Transcript will show once it’s been added to explainxkcd.com
Source: https://xkcd.com/3238/
Like toll booths on highways. Understood.
In QM however, neat particles don't exist, it deals with quantised, probabilistic waves. The above effect gets blurred over the waveform. No one atom definitely absorbs it or doesn't, it gets blurred together into a general slowing of the wavefront.
That's exactly the amount of QM I can understand. Which means I don't understand QM. ;)